1. Spearmint R2R3‐MYB transcription factor MsMYB negatively regulates monoterpene production and suppresses the expression of geranyl diphosphate synthase large subunit (MsGPPS.LSU)
- Author
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Niha Dhar, Chakravarthy Rajan, Deepa Panicker, Hui-Zhu Mao, Prasanna Nori Venkatesh, Nadimuthu Kumar, Rajani Sarojam, Qian Wang, Vishweshwaran Sridhar, and Vaishnavi Amarr Reddy
- Subjects
0106 biological sciences ,0301 basic medicine ,GPPS ,Gene Expression ,Secondary Metabolism ,R2R3‐MYB ,Plant Science ,Biology ,Sesquiterpene ,01 natural sciences ,Mentha spicata ,03 medical and health sciences ,chemistry.chemical_compound ,Gene Expression Regulation, Plant ,Gene expression ,Tobacco ,Oils, Volatile ,spearmint ,Plant Oils ,MYB ,Amino Acid Sequence ,Secondary metabolism ,Transcription factor ,terpene ,Research Articles ,transcription factor ,Phylogeny ,Plant Proteins ,Phenylpropanoid ,Base Sequence ,food and beverages ,Geranyltranstransferase ,Plants, Genetically Modified ,Diphosphates ,Plant Leaves ,030104 developmental biology ,chemistry ,Biochemistry ,Monoterpenes ,Ocimum basilicum ,Ectopic expression ,Diterpenes ,Agronomy and Crop Science ,Sesquiterpenes ,010606 plant biology & botany ,Biotechnology ,Research Article ,Transcription Factors - Abstract
Summary Many aromatic plants, such as spearmint, produce valuable essential oils in specialized structures called peltate glandular trichomes (PGTs). Understanding the regulatory mechanisms behind the production of these important secondary metabolites will help design new approaches to engineer them. Here, we identified a PGT‐specific R2R3‐MYB gene, MsMYB, from comparative RNA‐Seq data of spearmint and functionally characterized it. Analysis of MsMYB‐RNAi transgenic lines showed increased levels of monoterpenes, and MsMYB‐overexpressing lines exhibited decreased levels of monoterpenes. These results suggest that MsMYB is a novel negative regulator of monoterpene biosynthesis. Ectopic expression of MsMYB, in sweet basil and tobacco, perturbed sesquiterpene‐ and diterpene‐derived metabolite production. In addition, we found that MsMYB binds to cis‐elements of MsGPPS.LSU and suppresses its expression. Phylogenetic analysis placed MsMYB in subgroup 7 of R2R3‐MYBs whose members govern phenylpropanoid pathway and are regulated by miR858. Analysis of transgenic lines showed that MsMYB is more specific to terpene biosynthesis as it did not affect metabolites derived from phenylpropanoid pathway. Further, our results indicate that MsMYB is probably not regulated by miR858, like other members of subgroup 7.
- Published
- 2017